John wesley macknight



(No Model.)

J. W. MAGKNIGHT.

ARTIFICIAL STONE PAVEMENT. No. 389,311. 4 Patented Sept. 11, 1888.

WITNESSES. IN\/ENTEI p 5 y 4 JOHN \VESLEY MAOKNIGHT, OF NEW' YORK, N. Y.

ARTlFiClAL-STONE PAVEMENT.

SPECIFICATION forming part of Letters Patent No. 389,311, dated September 11, 1888.

Application filed November 11, 1887. Serial NLQFVLSBU.

T 0 all whom, it. 72mg concern.-

Be it known that I, JOHN W. MAGKNIGHT, of New York city, New York, have invented a new and Improved Artificial-StonePavement, of which the following is a specification.

Thisinvention has for its object to construct a pavement of artificial blocks in two horizontal layers of different material, which will be securely united at the joints, so as to prevent settling and the passage of water below,while at the same time they will be permitted to freely contract and expand, as more fully hereinafter specified.

In the accompanying drawing, the letters a a indicate the blocks forming the lower horizontal layer of the pavement, and b and b the superimposed blocks forming the upper or surface layer thereof.

The blocks a a are formed of a plastic flinty cement suitable to form a secure base or foundation for the upper or surface blocks, 1) b, which are composed of a more costly but a harder and better-wearing material.

In constructing the pavement, the bed upon which the pavement is to be constructed is laid off by means of joists, as usual, having spaces at alternateintervals ofsuitable size to form the proper molds for the blocks a a and b I), the inner sides of the joists being formed with bends or rabbets at the proper height to producethe grooves atthe upright edges ofthe said blocks a and b, as shown. The lower portions of said spaces are then filled to the horizontal line of intersection d with the flinty cement, which is allowed to set, when the finer cement to form the blocks 7) is filled into the top of the spaces or molds. WVhen the cement of the blocks b is set thejoists are removed, leaving intervening spaces between the grooved blocks thus formed. The vertical grooved edges of the blocks form ed (No model.)

in the first instance are then coated,by means of a brush or otherwise, with an elastic adhesive cement, 0, consisting, preferably, ofa mixture of one part of rubber, onepart ofasphalt, and one part of slag, cement, orlitharge. Atter this cement has properly set, the spaces between the grooved blocks a a and I) b are first filled to horizontal intersectinglined with the same flinty cement from which the blocks a are formedand the surface-blocks b are then formed by filling in the same cement as the surface-blocks b b. The cement forming the blocks a and b will enter the grooves in the upright adjoining edges of the blocks a a and b b,forming tongues therein,as plainly shown.

The completed pavement will thus be formed of two horizontal layers of interlocking blocks, the lower layers or base being all composed of the same fiinty cement and the upper layers of a finer and better-wearing cement, while the vertical joints will be united by a cement impervious to water, but at the same time of such nature as to permit the pavement to expand and contract freely without injuring the blocks or the pavement.

Having thus described my invention,what I claim, and desire to secure by Letters Patent, is-

An artificial pavement composed of a series ofcomposite blocks,cach block being composed of an upper wearing portion of different material from the lower portion, the said upper and lower blocks being united at a horizontal plane, which bisects a surrounding bead and groove interlocking the surrounding or adjacent block, substantially as specified.

JOHN \VESLEY lllACKNlG H'l.

\Vitnesses:

HENRY E. Bonner-z, l 'v. BRIESEN. 

